com.thinkberg.webdav.CopyMoveBase.java Source code

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Here is the source code for com.thinkberg.webdav.CopyMoveBase.java

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/*
 * Copyright 2007 Matthias L. Jugel.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.thinkberg.webdav;

import com.thinkberg.webdav.lock.LockException;
import com.thinkberg.webdav.lock.LockManager;
import com.thinkberg.webdav.vfs.VFSBackend;
import org.apache.commons.vfs.FileObject;
import org.apache.commons.vfs.FileSystemException;
import org.apache.commons.vfs.FileType;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.text.ParseException;

/**
 * The body of all COPY or MOVE requests. As these requests are very similar, they are handles mainly
 * by this class. Only the actual execution using the underlying VFS backend is done in sub classes.
 *
 * @author Matthias L. Jugel
 * @version $Id$
 */
public abstract class CopyMoveBase extends WebdavHandler {

    /**
     * Handle a COPY or MOVE request.
     *
     * @param request  the servlet request
     * @param response the servlet response
     * @throws IOException if there is an error executing this request
     */
    public void service(HttpServletRequest request, HttpServletResponse response) throws IOException {
        boolean overwrite = getOverwrite(request);
        FileObject object = VFSBackend.resolveFile(request.getPathInfo());
        FileObject targetObject = getDestination(request);

        try {
            final LockManager lockManager = LockManager.getInstance();
            LockManager.EvaluationResult evaluation = lockManager.evaluateCondition(targetObject, getIf(request));
            if (!evaluation.result) {
                response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
                return;
            }
            if ("MOVE".equals(request.getMethod())) {
                evaluation = lockManager.evaluateCondition(object, getIf(request));
                if (!evaluation.result) {
                    response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
                    return;
                }
            }
        } catch (LockException e) {
            response.sendError(SC_LOCKED);
            return;
        } catch (ParseException e) {
            response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
            return;
        }

        if (null == targetObject) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST);
            return;
        }

        if (object.equals(targetObject)) {
            response.sendError(HttpServletResponse.SC_FORBIDDEN);
            return;
        }

        if (targetObject.exists()) {
            if (!overwrite) {
                response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
                return;
            }
            response.setStatus(HttpServletResponse.SC_NO_CONTENT);
        } else {
            FileObject targetParent = targetObject.getParent();
            if (!targetParent.exists() || !FileType.FOLDER.equals(targetParent.getType())) {
                response.sendError(HttpServletResponse.SC_CONFLICT);
            }
            response.setStatus(HttpServletResponse.SC_CREATED);
        }

        // delegate the actual execution to a sub class
        copyOrMove(object, targetObject, getDepth(request));
    }

    /**
     * Execute the actual filesystem operation. Must be implemented by sub classes.
     *
     * @param object the source object
     * @param target the target object
     * @param depth  a depth for copy
     * @throws FileSystemException if there is an error executing the request
     */
    protected abstract void copyOrMove(FileObject object, FileObject target, int depth) throws FileSystemException;

}